Quote:
Originally Posted by pdurrant
I am reluctant to contradict your personal experience. If you assert that at 67 you have perfect distance vision in one eye, and yet can also read a 4.7" phone with that same eye (presumably holding the phone no more than 18 inches away), I have to concede that presbyopia seems not to be the universal condition that I thought it was. I have never heard of a 67-year-old retaining any amount of accommodation before.
I will clarify what I said, though, since you seem to have not quite understood what I meant.
By mono vision, I meant that you had one eye (the one with 'perfect vision') for distance vision, and the other (the slightly short-sighted one) for near vision. Some people with presbyopia (which is the condition we're discussing) choose to have glasses or contact lenses that produce this effect deliberately. It seemed to me that the way you described your vision, you have this effect naturally, thus 'natural mono vision'.
By '-2' I meant that your short-sighted eye might be short-sighted by an amount of 2 diopters. That is, its furthest focal point might be around 50cm. This would mean that you would be able to focus with this eye on things held around 50cm away from you, just as if you have normal distance vision and had +2 reading glasses.
And when talking about 'perfect vision', people almost always mean distance vision.
However, once again, I will defer to your personal experience, and change my claim from 'everyone' to 'very nearly everyone'.
As I say, I have never before heard of a case of a 60+ year old having any accommodation (the ability to change the focus of the eye) left at all. So I am very surprised.
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The primary intention of my original post was to relate my trick in exercising my eyes to fight off the "far sighted of the aged," which apparently has been working (after a few days with no close work, I require more time to regain my near focus via this exercising). It might work for others (it didn't for my nephew, who may have started too late).
My eye doctor is the one who said "perfect vision" in one eye. I don't know what that means, maybe he said it that way considering my age. Perhaps it was just a way of saying that eye didn't need corrective lenses for reading and tested 20/20 on distance. I know my vision has definitely deteriorated from when it was 20/12. But I don't need glasses, or at least my eye doctor doesn't write me a prescription. Trying each eye on distance shows they both do ok enough. Similarly with near. Occasionally some fine print, like gray on black, forces me to pull out a magnifying glass.
I'm a slow reader. My theory is that perhaps people who focus sharply on things (like a slow reader focuses on each word), can retain vision better than those who don't focus sharply, like speed readers. The 62-year-old school teacher with perfect vision (my term for her abilities) perhaps has the perfect mix of near and far focus exercise during her day, reading a lot and slowly, and looking sharply at her students.
P.S. I did understand what you meant by mono vision. I was just saying that apparently one eye must still be functioning on both near and far. Otherwise, at my age, it would have deteriorated quickly into its mono function.